Communications and signal processing requirements have changed greatly over the years due to a number of factors, such as the increasing information content, data resolution requirements and the wide variety of applications for the data. The associated equipments must be tested and evaluated more frequently to make certain that they are performing satisfactorily for their more highly sophisticated processing tasks. As a consequence, more complex signal generators and signal simulations are needed to give designers and technicians an accurate portrayal of some systems' actual capabilities. Heretofore a finite number of frequency synthesizers generated individual harmonics. Bandwidth simulations in the neighborhood of two kilohertz or less were found to need only four or five synthesizers for some purposes. The capability for extremely wide bandwidth testing realistically could not be provided for since a multitude of individual synthesizers would be required. Furthermore, a different harmonic content would require a different set of synthesizers. Many on the job test scenarios could not tolerate this burden because of the excessive bulk of equipment.
Thus, a continuing need exists in the state of the art for a extremely broad-band synthesizer having the capability of generating greater than 150 harmonics for the simulation or generation of the desired broad-band signal.